Pressure-pad-control device



May 24, 1927.

F. J. RODE' PRESSURE PAD CONTROL DEVICE I Filed April 1925 4 Sheets-Sheet 1 2? 11 32 29 30 O 33 I 16ml F. J. RODE PRESSURE PAD CONTROL DEVICE May. 24, 1927.

4 Sheets-Sheet 2 Filed April 1925 May 24, 1927. 1,629,538

F. J. RODE Y PRESSURE PAD CONTROL DEVICE Filed April 1925 4 Sheets-Sheet 3 May 24,1927. 1,629,538

F. J. RODE PRESSURE PAD CONTROL DEVICE Filed April @925 4 Sheets-Sheet 4 Patented May 24, 1927.

UNITED STATES PATENT OFFICE.

FRIEDRICH J. RODE, OF CHICAGO, ILLINOIS, ASSIGNOR TO MARQUETTE TOOL 80 MANU- FACTURING (10., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PRESSURE-PAD-CONTROL DEVICE.-

. Application filed April 20,1925. .Serial No. 24,695.

This invention relates to improvements in pressure pad control device particularly adapted, though not necessarily limited in its use, in connec a ing presses.

In presses of this character it is custom ary to provide the drawing dies with blank holding means which in turn is provided with cushioning means embodying what is 'com- In monly known as a pressure pad for controlling the degree of pressure'at which the work is held, and which cushioning means is released at the bottom of the stroke of the when theram of the press is moving upwardly, thereby causingwhat is commonly known as back lash. This back lash takes I place at the time when the crank of the press press is passing-over the center point at the bottom of its stroke or circular movement.

It is one of the objectslof the present invention to provide improved means for con trolling the return movement of the pressure pad and for holding the pad against return movement so that it will not return or move upwardly with the punch or ram on the return stroke, but will be held by the blank holding means until the latter is returned and will return with the blank holder on the upstroke.

This will cause the pressure pad to travel upwardly gradually and will prevent the pressure pad from slamming.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more fully described and claimed and shownjn the accompauying drawings illustrating this invention, and in which.

Figure l is a view partly in'el'ev'ation, partly in vertical section and partly broken away of a portion of a sheet metal drawing press constructed in accordance with the principles of this invention, and showing the parts in the positions they will assume when the ram is in its uppermost position. I

Figure 2 is a 'view similar to Figure 1, showing the parts in the positions they will tion with sheet metal drawassume just at the completion of the draw ing operation and before the ram starts to ascend.

Figure 3 is a view similar to Figure 1, of a modified form of the invention.

- Figure 4 is a view similar to Figure 2, of the form of the invention shown in Figure 3.

Figure'.) is a detail sectional view taken on line 55, Figure 3.

Referring more particularly to the drawings the numeral 10 designates generally the bed plate ofa press to which is secured a die 11, and within which die 11 is arranged a movable die 12. Disposed beneath the press and support in any suitable manner is a cushioning device designated generally by the reference numeral 13 and in which y w o I a I o cushloning device there 1s reciprocable a piston (not shown), having a rod 14 connected thereto which projects beyond the cylinder and has connected at its upper end a pin plate 15. Passing through the bed plate 10 are pins 16 which rest upon the pin'plate 15 and support the die member 12. H

The cylinder 13 is supported in any suitable manner such as by means of rods or hangers 17 secured by one extremity to a fixed'portion of the press.

The ram of the press has connected with .itadie member 18, the active'face of which corresponds with the active face of the die member 12, and the ram to which the die member 18' is connected is reciprocable through the medium of a crank shaft 19 having cranks 20 connected therewith,-and which cranks. are connected in a suitable manner 'such as by'means of the links 21 with the. ram. I i The die member 18 is disposed within a blank holding member 22, which in turn is carried by a reciprocati is operated by means of cranks 24 through the medium of links 25. The blank holding ng member 23 that" member 22 co-operates with the die member 11 for clamping and holding the material to be shapedby the die members 12 and 18, all I of wh ch parts, are of theordinary an Connected with the pin plate -15 so as to -move therewith is a member 26 which is prefjustably connected to the member 26 in any.

suitable manner, preferably by means of one extremity passing through the member and being threaded, the threaded portion of each of the members 27 being adapted to receive nuts or collars 28 through the medium of which the rods 27 may be adjusted with respect to the member 26.

These rods or inembers27 pass loosely through the bed plate 10 and are adapted to project for any desired distance thereabove.

Pivotally connected with each of the rods or members 27 in any suitable manner, is a member 29, the portion 30 of which on one side of the pivot is preferably weighted or is of a heavier construction than the portion on the other side of the pivot. The end or portion 31 of the member 29 is so shaped that when the member 29 assumes the position shown in Figure 2, the member 31 will engage and rest upon the top of the rod or member 27 and will be disposed within the path of the downward movement of a menr ber 32 which is adjustably connected in any suitable manner with the blank holding member 22.

Any number of these rods or members 27 and the cooperating member 29 may be provided, and one member 32 will be provided for each of the rods or members 27;

Connected with the base plate 10 and at a suitable position with respect to the pivot of the member 29, is a projection 33, which under certain conditions when the rods or members 27 are lowered from the position shown in Figure 1, will engage the respective members 29 on one side of the pivot thereof to rock the members 29 from the position shown in Figure 1 to the position shown in Figure 2, to form an extension for the respective rods or members 27.

The rocking of the members 29 will take place after the blank holding member 22 has engaged the work and clamped the same against the edge of the die 11. At this time the die 18 will begin to descend and when 1t engages the work it will force the work into the die 11 and against the die 12, the latter be1ng lowered througlr the medium of the pins 16 and p n plate15, piston rod 14 and piston against the pressure in the cylinder 13. Asthe die .12 descends and as the member 26 carrying the rods or members 27 is connected withthe pin plate 15, it will also descend and carry with it the rods or members 27, causing the members 29 to be lowered from the positionshown in Figure "1 until they contact with the projections 33. A further lowering movement of the die 12 and the associated parts will cause the member's 29 to be rocked about their pivots by the of the press or the point at which the crank of the press is passing over the center point. At this time and as the ram with the die 18 starts to ascend pressure upon the die 12 by the die 18 will be relieved and the tendency of the die 12 under the influence of the pressure in the cylinder 13, would be to follow the die 18 but, as the blank holding member 22 is still retained in its lowermost position until after the-die 18 has started to rise, the die 11 will be prevented from rising with the ram and die 18 by reason of the fact that the end of the portion 31 of the member 29 will engage the projection 32 and the die 12 will be held against rising by means of the blank holder 22. As the blank holder 22 begins to rise the pressure in the cushion 13 will cause the d1e'12 to rise, and as the die 12 rises the rods or members 27 will rise. During this raising movement and as the members 29 are overbalanced at the end 30 the members will rock from the position shown in Figure 2 to that shown in Figure 1, thereby resulting in a gradual return movement of the die ,12 under the influence of the pressure in the cushion. This will prevent a quick return of the die 12 and pressure pad and obviate slamming.

In the form of the invention shown in Figures 3 -and 4, the rods or members 34 which correspond with the rods or members 27, have respectively pivotally connected with them. as at 35, one end of a toggle formation 36; The other end of the toggle is pivotally connected as at 37 with a member 38. This member 38 is preferably guided in its movement by means of a guide 39 which is connected with the bedor bolster plate 10 and is disposed in close proximity to the path of movement of the member 38 and the rod or member 34. The member 38 is preferably provided with a clove tail groove 40 into which a corresponding projection 41 carried by the member 38 operates. Arrangedwith'in the path of movement of one of the members of the toggle is an adjustable member 42 which is adapted, when the rodsor members '34 are lowered, to respectively engageone .of the members of the toggle and move the toggle from the posi- 1e5- The member 38 nortoggle is straightened out the members 38 and 34 move away from each other and the member 38 will be projected into the path of movement of the projection or extension 32 carried by the blank holding means 22.

A weight or other suitable means 45 may be connected with the toggle and is so ar-- ranged that it will have a normal tendency to knuckle the toggle.

The operation of this form of the invention is the same as that disclosed in connection with the form shown in figures l and 2.

The normal position of the parts, that is when the press is not in operation, is that shown in Figure 3. \Vhen the ram descends the work will be clamped between the blank holding means 22 and the die 11, and at the time that the blank holding means is arrested in its downward movement the end of the projection 33 will stand in close proximity to the end of the member 38. Vhen pressure is exerted upon the die 12 by the die 18, through the descending of the ram or member 26 when it is lowered, it will draw with it the rods or members 34; causing the toggle 36 to be straightened out by reason of a portion of the toggle moving in contact with the end of the member 42.

As the die 12'reacnes the limit of its lowering movement the toggle will be straightened out until the pivots 35-36 and the intermediate pivot 46, will be brought into alinement as shown in Figure 4, thereby locking the member 38 and the rod or member 34 against movements in directions towards each other. At thistime the end of the member 38 will be in contact with the end of the projection 32. When the ram carrying the die 18 ascends the die 12 will be held against a following movement by reason of the fact that it will be held down through the medium of the member 38 and toggle 36 connected with the rod or member '38. As the blank holder 22 rises the die 12 will follow and as the rods or members 38 rise the weights 45 connected with the respective toggles 36 will gradually knuckle them over the end of the respective projections 42.

Thus it will be seen that the pressure pad will travel upward gradually and will be prevented from slamming back.

The upward movement of the die 12 and the pin plate 15 during the upward movement of the blank holder. may be arrested in any desired or suitable manner such as by means of adjustable stop devices 47 carried by the member 26, and which are adapted to engage a suitable portion 48 of the press.

While the preferred forms of the invention have been herein shown and described it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

\Vhat is claimed as new is 2- 1. A draw press including a plunger, work holding and-gripping means, a die, a pressure cushion for the die, and freely swinging means insertable between the cushion and work holder whereby the said work holding means will maintain the said die from tol lowing the upward movement of the plunger, the. last recited means operating to permit the pressure cushion to return the die upon the return movement of the work holding means.

2. A draw press including a plunger, work holding and gripping means, a die, a pressure cushion for the die, and freely swinging means responsive in its operation to the operation of the said die and insertable between the cushion and work holding means for maintaining the said die from following the upward movement of the plunger, the lattrecited means being rendered inactive upon the return movement-of the work holding means.

3. A draw press including a plunger, work holding and gripping means, a die, a pressure pad for the die, and freely shiftable means adapted to be automatically positioned to be engaged by a portion of the plunger at a predetermined time in the cycle of operation of the press for positively locking the said pressure pad at the bottom end of the stroke of the press.

4. A draw press including a plunger, work holding and gripping means, a die, a pressure pad against the stress of which the die is operable, and mechanical means adapted' to be automatically interposed between the blank holding means and the said pad for locking the die in the osition it will assume at the lowermost end of the stroke of the press. j

5. A draw press including a plunger, work holding and gripping means, a die, a pressure pad against the stress of which the die is operable, and mechanical means responsive in its operation to the movement of the die and embodying means adapted to-be automatically interposed between the said llt) pad and the blank holding means for locking the pad against operation and at the lowermost end of the stroke of the press.

6. A draw press including a plunger, work holding and gripping means, a die, a pressure pad for the die, opposed formations connected respectively with the said pad and work holding and gripping means and movable-in directions towards and away from each other, and-means adapted to be automatically interposed between said formations to lock the said pad at the bottom of the stroke of the press and against return movement with the plunger.

7. A draw press including a plunger, work holding and gripping means, a die, a pressure pad for the die, opposed formations connected respectively with the said pad and work holding and gripping means and movable in directions towardsand away from each other, and means responsive in its operation to the movement of the said die and adapted to be inserted between the said formations to lock the said pad against return movement with the upward movement of the said plunger.

8. A draw press including a plunger, work holding and gripping means, a die, a pressure pad for the die, opposed formations connected respectively with the said pad and work holding and gripping means and movable in directions towards and away from each other, and means adapted to be automatically interposed between said formations to lock the said pad at the bottom of the stroke of the press and against return movement with the said plunger, the last said means including a pivotally mounted element and means for swinging said element about its pivot.

9. A draw press including a plunger, a work holding and gripping means, a die, a pressure cushion for the die, positive means whereby the said work holding means will maintain the said die from following the upward movement of the plunger, the last recited means embodying an over-balanced element pivotally connected to avsupport movable with the said die, and means for contacting and rocking said element as the plunger approaches the end of its working stroke, for positioning the said element between the Work holdingand gripping means and the said plunger for locking the work holding means at the end of the stroke of the press.

In testimony whereof I have signed my name to this specification, on this 15th day of April, A. 1925.

FR'EDRICH J. RODE. 

